The Effects of Inbreeding in Golden Retrievers

The general rule for responsible breeders is that inbreeding should be avoided. Inbreeding is when a male or female adult dog is bred with a relative of that dog (e.g., brother, sister, parent, grandparent, cousin, etc.). However, if you go back far enough in a dog's family tree, virtually every pure-bred dog will have traces of inbreeding, primarily because of the age of our country and the population of pure breeds in this country. Keep in mind the American Kennel Club, which maintains the largest registry of pure-bred pedigrees in the U.S. was only formed in 1884, and the Kennel Club of England (the first and oldest pure-bred dog registry in the world) was started in 1873. The Golden Retriever breed itself has only been around for a little more than a 150 years, originating in the highlands of Scotland. If you think about a pure-breed’s origins, in order to stay within that breed and not cross into another breed, inbreeding was necessary. So, the further you go back in time in this country and throughout the world for the Golden Retriever, the sheer numbers of the breed become fewer and fewer. Thus, inbreeding was inevitable and certainly more prevalent than it is today.

But there are also some justifiable reasons for inbreeding: when certain traits such as color, physique, or temperament are sought after in certain dogs, some breeders will use a related male and female with those desirable traits to increase the chances of those traits in the offspring. Traditionally in the past, Golden Retriever breeders fairly commonly used grandfather/grand-daughter matings (and often times even closer related) to emphasize certain traits and make them dominant in subsequent generations. In reality, inbreeding is precisely what occurs in the origins of any pure-bred dog. Not as much inbreeding occurs today, but it does occur. So, what are the problems with inbreeding if it is done purposely? There are two primary problems:

No Golden Retriever is 100% healthy and problem free throughout its life. There will always be some traits that are weaker, more subject to disease, and may develop into health issues in a Golden Retriever’s lifespan. It’s just the nature of anatomy. So, if a potentially unhealthy trait of some kind is in a particular dog’s genes, and it is mated with a close relative, then that relative also has the same unhealthy trait. In their mating, that trait would be emphasized in the offspring. This can cause a rapid buildup of diseased genes in the lineage of a Golden Retriever; and

Even if a Golden Retriever is free from any serious genetic disorders, inbreeding can result in breeding problems in future litters of the offspring, less vigorous or viable puppies in those future litters, a weakened immune system in those future pups, and a shorter lifespan. These types of problems are known as “inbreeding depression”.

With those two points being made, inbreeding should not be completely dismissed and characterized overall as a bad thing, because in genetics, nothing is concrete because of all the variables. There are some very good examples in the dog breeding world of highly inbred lineages that appear to be very healthy, very viable, and very fertile litter after litter. Conversely, if there is a low degree of inbreeding in the lineage of a dog, it does not guarantee that dog’s offspring will be free from genetic disorders or health issues. But, if there is a high degree of inbreeding, it should cause some concern because it may result in a higher probability of health issues in that dog’s offspring.

Okay, if there is always some degree of inbreeding found in the family tree of a Golden Retriever, how much is too much and how much is acceptable? In England, where the dog population is smaller than in the U.S., and inbreeding is far more likely, veterinary geneticists have developed a measurement of the degree of inbreeding called the, “Coefficient of Inbreeding” (or COI). They have also established guidelines for the amount of inbreeding that is considered healthy and acceptable in good breeding practices. The COI can be analyzed for any dog if the pedigree of that dog is known for the recommended minimum of at least five generations.

We think that a responsible breeder should consider the pedigrees of the dogs they use in their breeding program to avoid genetic health issues and the possibility of premature death caused from a build-up of diseased genes and genetic disorders (inbreeding depression). Currently, the best way that responsible breeders can prevent or minimize this as much as possible, is to take a very detailed look at the Coefficient of Inbreeding, COI, which is expressed as a percentage and is sometimes referred to as IC, WIC, Fx, or F in various studies over the years. The lower the COI percentage, the less chance of “inbreeding depression”, according to the geneticists who have studied this topic for decades.

To determine the COI percentage, the ancestral lineage of the parents need to be known for at least five generations. Then, these have to be evaluated by a calculation using a rather complicated formula, which if you think about it can become pretty complex considering there are 62 males and 62 females in a five generation pedigree. So then, to evaluate the suitability of a particular male and female for breeding purposes, there are 126 dogs that have to be included in the analysis! This requires something like a spreadsheet is required to do this complicated evaluation of the COI percentage. Here are some points to help understand how COI works when evaluating the acceptability of a male and female for breeding purposes. The following COI percentages occur after only one generation of puppies are considered. The percentages become smaller as more unrelated generations are included in the COI analysis:

Parent/offspring: 25%

Full siblings: 25%

Grandparent/grandchild: 12.5%

Half siblings: 12.5%

Great grandparents/great grandchild: 6.25%

First cousins: 6.25%

The lower the COI, the less chance of inbreeding depression. Here are some additional points to consider:

The ideal COI for five generations would be 0% (this is becoming more and more uncommon in Golden Retrievers because many of today's newest breeders do not put much thought into the lineage of their breeding dogs).

Experts in the field of genetics recommended the maximum COI for five generations should be around 6% to reduce the chances of “inbreeding depression” (this is equivalent to mating first cousins, or grandparent/grandchild).

We at Golden PuppiesTM think 6% is way too high unless a very thorough health screen in all possible areas of the male and female Goldens are obtained, and parents on both sides of the Goldens are known to have had an excellent health history. A COI of 6% is not entirely uncommon among some breeding professionals, especially imported dogs.

The preferred COI for five generations according to some experts should be lower than 3% to avoid or minimize “inbreeding depression”. At Golden PuppiesTM, we agree that having a COI as low as possible should be the goal.

There is a caveat with COI because it can sometimes be a little misleading and show a percentage of nearly 0% if a brother and sister are mated but the five generations before them are entirely unrelated. To overcome this potentially misleading problem, another evaluation called “Ancestor Loss Coefficient”, or AVK should also be evaluated from the pedigrees of the parents. According to experts, the AVK should be higher than 85% to avoid “inbreeding depression” and promote good genetic health. The higher the AVK percentage, the better chance of avoiding “inbreeding depression”. Both COI and AVK should be considered before breeding a male and female Golden Retriever.

If you want to know more about this subject, click here for an excellent article designed for the lay person to understand. In addition, a teaching video on calculating the Coefficient of Inbreeding can be viewed here. And finally, we have determined the COI and AVK for litters produced by all of the dogs in our Golden PuppiesTM breeding program. They are as follows:

Expert Recommended Values:

Less than 3.0%

Greater than 85%

Duke and Helaina (our white cream litters)

COI = 0.0%

AVK = 90%

Huck and Duchess (our white cream litters)

COI = 0.0%

AVK = 90%

Oliver and Lexi (our light blonde litters)

COI = 0.0%

AVK = 95%

Rhett and Scarlett (our caramel litters)

COI = 0.0%

AVK = 97%

Beau and Willow (our auburn litters):

COI = 0.2%

AVK = 90%

We hope this article is helpful to those who are concerned about inbreeding, and perhaps to those who have experienced helath problems or loss of their Golden Retriever and suspect it may have been due to a high percentage of inbreeding. If this is something you want to explore a little more, give us a call and perhaps we can help you determine if inbreeding was potentially the cause of your loss. Thank you for considering Emery-n-Denise's Golden PuppiesTM

We are exclusively a Golden Retriever Breeder of AKC pure bred Golden Retrievers and we have Golden Retriever Puppies for sale in Virginia and Washington.